May 2017 doc.: IEEE 802.11-17/0730r1
IEEE P802.11
Wireless LANs
Date: 2017-05-03
Author(s):
Name / Affiliation / Address / Phone / email
Kiseon Ryu / LG / Yangae 11gil, Seocho-gu, Seoul, Republic of Korea / +82-10-2356-6164 /
Interpretation of a Motion to Adopt
A motion to approve this submission means that the editing instructions and any changed or added material are actioned in the TGax Draft. This introduction is not part of the adopted material.
Editing instructions formatted like this are intended to be copied into the TGax Draft (i.e. they are instructions to the 802.11 editor on how to merge the text with the baseline documents).
TGax Editor: Editing instructions preceded by “TGax Editor” are instructions to the TGax editor to modify existing material in the TGax draft. As a result of adopting the changes, the TGax editor will execute the instructions rather than copy them to the TGax Draft.
CID / PP.LL / Comment / Proposed Change / Resolution7255 / 49.11 / It's not clear how to construct an A-MPDU in the HE trigger-based PPDU when the Multi-TID
Aggregation Support field of the HE Capabilities element is set to 0. For that case, MPDU aggregation in an A-MPDU according to the Preferred AC subfield in the Basic Trigger frame should be clarified. / Modify the text as below:
The Preferred AC subfield indicates the AC that is recommended for aggregation of MPDUs of ACs belonging to the same AC as indicated or higher priority AC(s) within a multi-TID A-MPDU sent as a response to the Trigger frame (see 9.3.1.23 (Trigger frame format)). The encoding of the Preferred AC subfield is shown in Table 9-25i (Preferred AC subfield encoding). If the TID Aggregation Limit subfield is set to 1, the MPDUs with a TID belonging to the same AC as indicated in the Preferred AC subfield should be aggregated in the A-MPDU. If the TID Aggregation Limit subfield is set to 1 and there is no MPDU with a TID belonging to the same AC as indicated in the Preferred AC subfield, MPDUs with a TID belonging to the higher priority AC may be aggregated in the A-MPDU. / Revised.
Agree in principal.
It needs to be specified in the section describing the normative behaviour.
TGax editor make the changes as shown in 11-17/0730r1.
Discussion:
• The following text is described in D1.2.
• An HE STA with dot11AMPDUwithMultipleTIDOptionImplemented set to false should select any one of the TID value within the AC value indicated in the Preferred AC subfield in the Trigger Dependent User Info field of a Basic Trigger variant Trigger frame.
• An HE STA with dot11AMPDUwithMultipleTIDOptionImplemented set to false may select a TID from any AC when the Preferred AC subfield is AC_BK in the Trigger Dependent User Info field of a Basic Trigger variant Trigger frame.
If a STA not supporting multi-TID A-MPDU aggregation and has no buffered BU for the TID belonging to the same AC value indicated in the Preferred AC subfield in the Basic Trigger frame,
- Option 1: STA may or may not transmit a QoS Null frame in the HE TB PPDU.
- Option 2: STA may transmit MPDUs for a TID belonging to the higher priority AC in an A-MPDU carried in the HE TB PPDU.
- Option 3: STA may transmit MPDUs for any TID in an A-MPDU carried in the HE TB PPDU.
Option 1 is less efficient and option 3 is not compatible with the rule to construct the A-MPDU defined in 27.10.4. Therefore, option 2 is preferred.
Propose:
Revised for CID 7255 per discussion and editing instructions in 11-17/0xxxr0.
TGax editor: Modify the sentence on page 216 line 5 as the following:
27.10.4 A-MPDU with multiple TIDs
…
An HE STA with dot11AMPDUwithMultipleTIDOptionImplemented set to false should select any one of
the TID value within the same or higher priority(#7255) AC value indicated in the Preferred AC subfield (#3018)in the Trigger Dependent User Info field of a Basic Trigger variant Trigger frame. If the HE STA has no buffered MPDU for TIDs belonging to the same or higher priority AC indicated in the Preferred AC subfield in the Trigger Dependent User Info field of a Basic Trigger variant Trigger frame, the HE STA may transmit MPDUs for a TID belonging to other AC in an A-MPDU carried in the HE TB PPDU(#7255).
An HE STA with dot11AMPDUwithMultipleTIDOptionImplemented set to false may select a TID from any AC when the Preferred AC subfield is AC_BK(#3018) in the Trigger Dependent User Info field of a Basic Trigger variant Trigger frame.
NOTE—A multi-TID A-MPDU allows the aggregation of an Action Ack frame as well.
An HE AP may aggregate MPDUs from any TIDs in multi-TID A-MPDU for DL HE MU PPDU transmis-sion and the number of TIDs in multi-TID A-MPDU shall not be more than the Multi-TID Aggregation Sup-port announced by the recipient.
Submission page 3 Kiseon Ryu, LG